Nuprl Lemma : continuous-minus

∀[I:Interval]. ∀[f:I ⟶ℝ].  (f[x] continuous for x ∈ I ⇒ -(f[x]) continuous for x ∈ I)


Proof




Definitions occuring in Statement :  continuous: f[x] continuous for x ∈ I,  rfun: I ⟶ℝ,  interval: Interval,  rminus: -(x),  uall: ∀[x:A]. B[x],  so_apply: x[s],  implies: P ⇒ Q
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  continuous: f[x] continuous for x ∈ I,  all: ∀x:A. B[x],  member: t ∈ T,  sq_exists: ∃x:{A| B[x]},  and: P ∧ Q,  cand: A c∧ B,  prop: ℙ,  so_lambda: λ2x.t[x],  nat_plus: ℕ+,  so_apply: x[s],  rfun: I ⟶ℝ,  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  rless: x < y,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  label: ...$L... t,  squash: ↓T,  true: True,  subtype_rel: A ⊆r B,  rsub: x - y,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  radd_comm,  rminus-rminus,  req_transitivity,  req_inversion,  rminus-as-rmul,  rmul_functionality,  radd_functionality,  req_weakening,  rminus-radd,  rabs_functionality,  rleq_functionality,  uiff_transitivity,  rmul_wf,  radd_wf,  iff_weakening_equal,  rabs-rminus,  true_wf,  squash_wf,  interval_wf,  rfun_wf,  continuous_wf,  icompact_wf,  set_wf,  nat_plus_wf,  int_formula_prop_wf,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_less_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermVar_wf,  itermConstant_wf,  intformless_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__lt,  nat_plus_properties,  rless-int,  rdiv_wf,  i-member-approx,  rminus_wf,  less_than_wf,  all_wf,  int-to-real_wf,  rless_wf,  real_wf,  i-approx_wf,  i-member_wf,  rsub_wf,  rabs_wf,  rleq_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  sqequalHypSubstitution,  cut,  hypothesis,  dependent_functionElimination,  thin,  hypothesisEquality,  setElimination,  rename,  dependent_set_memberFormation,  productElimination,  independent_pairFormation,  because_Cache,  independent_functionElimination,  lemma_by_obid,  isectElimination,  productEquality,  natural_numberEquality,  sqequalRule,  lambdaEquality,  functionEquality,  dependent_set_memberEquality,  applyEquality,  independent_isectElimination,  inrFormation,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  setEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  baseClosed,  universeEquality,  minusEquality

Latex:
\mforall{}[I:Interval].  \mforall{}[f:I  {}\mrightarrow{}\mBbbR{}].    (f[x]  continuous  for  x  \mmember{}  I  {}\mRightarrow{}  -(f[x])  continuous  for  x  \mmember{}  I)



Date html generated: 2016_05_18-AM-09_11_38
Last ObjectModification: 2016_01_17-AM-02_38_34

Theory : reals


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